Microbiology Commons^™

Investigating Links Between Soil Microbial Structure And Function In Three Major Plant Communities Across Temporal Scales Of Arctic Alaska, Kaj Lynoe

Electronic Theses and Dissertations

Arctic microbial systems continue to get attention today as our understanding regarding their structure and function in a changing system is paramount to C feedbacks with warming and changes in precipitation. Plant communities and microbial community processes across the Arctic landscape are central to understanding tundra ecosystem processes because environmental conditions and plant community structure drive microbial cycling of soil organic matter. Here, we want to understand how soil microbial respiration, mineralization, biomass, and community composition are linked to three Alaskan tundra plant communities, namely Shrub, Tussock, and Sedge tundra and the seasonal variability in this system. A total of …

Developing Microbial Based Process To Produce High Value Natural Antimicrobial (Glyceollin) In Soybeans And Pullulan From Sucrose, Andrea Zavadil

Electronic Theses and Dissertations

Glyceollin is a secondary metabolite produced under stress conditions by soybean to act as a plant defender to pathogen attack. The antimicrobial nature of glyceollin makes it a promising natural alternative to antibiotics if incorporated into livestock feed. However, production of glyceollin is highly variable, dependent on soybean variety, and fungal elicitor used as inoculum. Our study compares two fungal spore elicitors, Trichoderma reesei and Aspergillus sojae on soybeans of diverse maturity level, and fungal susceptibility to determine highest glyceollin titer. Spore inoculation with T. reesei elicited highest glyceollin titers of 2.42±0.20 mg/g at 120 h, while A. sojae elicited …

Mass Spectrometry Based Lipidomic Investigation Of Staphylococcus Aureus Lipid Metabolism And Characterization Of Lipase A, Naren Gajenthra Kumar

Theses and Dissertations

Staphylococcus aureus produces an arsenal of virulence factors and is adept at colonizing multiple hosts by employing specific processes to persist at different sites of infection. Infections caused by this pathogen range from self-limiting infections of the skin like folliculitis to life threatening and chronic conditions like infective endocarditis, non-healing diabetic foot ulcers and atopic dermatitis. As the field continues to expand its understanding of the mechanisms by which this pathogen rapidly develops resistance to new antibiotics, the underlying mechanisms that facilitates niche adaptation and host colonization among healthy individuals remain elusive.

Bacterial and host lipid metabolism presents and area …

The Antimicrobial Activity Of Silicon Copper Nanoparticles, Angela Mangano

Sustainability Research & Creative Activities Grants Reports

Excessive overuse of antibiotics has led to the emergence of mutations within bacteria that result in drug resistance. In an effort to combat the expanding issue of drug resistance, nanoparticles' bactericidal capabilities are being researched as an alternative to antibiotics (Beyth, 2015). In this paper, research to explore a novel silicon copper nanoparticle's antimicrobial capabilities will be discussed. The novel nanoparticle was developed by West Chester University professor, Dr. Kolasinski. The specific research goals were to determine the time and dose dependency of the nanoparticles and investigate the antimicrobial spectrum of activity against Gram-positive bacteria, Gram-negative bacteria, and viruses. Gram-positive …

Characterization Of The Putative Polysaccharide Synthase Cpsa And Its Effects On The Virulence Of The Human Pathogen Aspergillus Fumigatus, Binita Nepal

Graduate Research Theses & Dissertations

The fungus Aspergillus fumigatus is a ubiquitous opportunistic human pathogen capable of causing a life-threatening disease called invasive aspergillosis, or IA, with an associated 40–90% mortality rate in immunocompromised patients. Of the approximately 250 species known in the genus Aspergillus, A. fumigatus is responsible for up to 90% of IA infections. This study focuses on examining the role of the putative polysaccharide synthase cpsA gene in A. fumigatus virulence. Additionally, we evaluated its role in cellular processes that influence invasion and colonization of host tissue. Importantly, our results support that cpsA is indispensable for virulence in A. fumigatus infection of …

Bioinformatic Anlayses Of Identified But Uncultivated Microbial Dark Matter Organisms Using Archival Single Amplified Genomes (Sags), Daniel Adam Nuccio

Graduate Research Theses & Dissertations

This project characterizes two independent, previously undescribed microbial dark matter organisms from the candidate phyla JL-ETNP-Z39 and NBK19. These characterizations are based on seven single amplified genomes (SAGs) for JL-ETNP-Z39 and six SAGs for NBK19. All SAGs used were provided by the Bigelow Laboratory for Ocean Sciences Single-Cell Genomics Center (scgc.bigelow.org). Bioinformatic analyses using a combination of publicly available software and custom scripting written in the computer programming languages Python and R were carried out to determine the basic genomic properties, evolutionary relatedness, representative environmental pangenomes, and metabolic properties of these organisms. Analyses indicated that the examined JL-ETNP-Z39 SAGs are …

Acetaldehyde Production By Rothia Mucilaginosa Isolates From Patients With Oral Leukoplakia., Abdrazak Amer, Aine Whelan, Nezar N. Al-Hebshi, Claire M. Healy, Gary P. Moran

Articles

Rothia mucilaginosa has been found at high abundance on oral leukoplakia (OLK). The ability of clinical isolates to produce acetaldehyde (ACH) from ethanol has not been investigated. The objective of the current study was to determine the capacity of R. mucilaginosa isolates recovered from OLK to generate ACH. Analysis of R. mucilaginosa genomes (n = 70) shows that this species does not normally encode acetaldehyde dehydrogenase (ALDH) required for detoxification of ACH. The predicted OLK metagenome also exhibited reduced ALDH coding capacity. We analysed ACH production in 8 isolates of R. mucilaginosa and showed that this species is capable of …

Characterization Of Ovine Ileal Epithelial And Myofibroblast Cell Lines And Their Role In Innate Immunity, Shaurav Bhattarai

Electronic Theses and Dissertations

Development of continuous cell lines has been an indispensable tool for studying disease pathogenesis at cellular and molecular level. Intestinal epithelial cells serve as a barrier between the luminal contents and internal tissue and face unique challenge in maintaining homeostasis. Any form of disruption in the uppermost intestinal epithelium exposes underlying intestinal subepithelial myofibroblast (ISEMF) cells to the luminal content, which results in the generation of immune responses from ISEMF cells. Our main goal was to establish and characterize intestinal epithelial and myofibroblast cell lines from a 3-day old sheep. ISEMF cells play significantly important role in wound healing, tissue …

Utilizing Rhizospheric And Bacterial Endophytes For Use As Potential Bio-Fertilizers For Sustainable Agricultural Production, Vincent Peta

Electronic Theses and Dissertations

Brassica carinata crop production offers an exciting alternative approach to the energy crisis when looking at novel ways to power our motor vehicles. Bacterial endophytes, while residing in host-plant tissues, offer a wide array of plant growth promotion benefits such as nitrogen fixation to impart nitrogen (N) nutrition, phosphate (P) solubilization to make soil-bound phosphate more mobile in soil for plant uptake, can suppress pathogenic microbes such as fungus and produce plant growth hormones to offset stress incurred by the plant. Previous literature has shown that there is large interest in studying endophytes from economically important crops such as wheat, …

Epitope Mapping And Mechanisms Of Action Of Human Influenza Antibodies Derived From Transchromosomic Cattle, Rongyuan Gao

Electronic Theses and Dissertations

Influenza remains a global health risk and challenge. Currently, NA inhibitors are extensively used to treat influenza, but their efficacy is compromised by the emergence of drug resistant variants. Antibodies targeting influenza A virus surface glycoproteins are critical components of influenza therapeutic agents and may provide alternative strategies to the existing countermeasures. This study characterized both polyclonal and monoclonal antibodies produced from the transchromosomic (Tc) cattle platform. A polyclonal antibody, designated SAB-100, was generated from Tc cattle after immunized with H1N1,H3N2, and influenza B virus. The peptide-based Enzyme-linked immunosorbent assay shows that the polyclonal antibody recognizes three distinct epitopes, one …

Crispr/Cas9 Whole Genome Screens Reveal Novel Regulators Of Endocytic Processes In Macrophages, Jared Wollman

Electronic Theses and Dissertations

Macrophages maintain tissue homeostasis by identifying and eliminating threats within their tissue microenvironment. Pattern recognition receptors allow macrophages to recognize and internalize specific ligands while macropinocytosis allows the internalization of all extracellular solutes from their environment. Without pattern recognition receptors, pathogens may grow unchecked if they cannot be detected, and without macropinocytosis, macrophages struggle to detect and move around their environment. This thesis presents the results of CRISPR/Cas9 whole-genome screens used to identify the regulators of both endocytosis (Chapter 2) and macropinocytosis (Chapter 3). In Chapter 2, we report genes regulating dextran uptake in primary murine macrophages and reveal Mrc1-mediated …

Adaptation Of Vibrio Cholerae O1 To Protective, Lipopolysaccharide-Specific Antibodies In The Intestinal Lumen, Danielle Elizabeth Baranova

Legacy Theses & Dissertations (2009 - 2024)

The outer membrane (OM) of Gram-negative enteric pathogens like Vibrio cholerae is a barrier against host defense factors, as well as a sensor of physical and chemical stimuli that the bacteria encounter in the gastrointestinal tract. The OM is also the primary target of the mucosal immune response, which consists of secretory antibodies primarily directed against lipopolysaccharide (LPS). ZAC-3 is a monoclonal antibody (MAb) that targets the conserved core/lipid A region of LPS of the pandemic V. cholerae O1 serotype. In a neonatal mouse model, passively administered ZAC-3 IgG has been shown to reduce the ability of V. cholerae to …

Molecular Mechanisms Shaping Host Range Of A Vector-Borne Pathogen, Thomas Macgregor Hart

Legacy Theses & Dissertations (2009 - 2024)

Vector-borne diseases, such as Lyme disease caused by Borrelia burgdorferi sensu lato (Bbsl), have narrow host ranges and are apt models to study host-microparasite coevolution. Some species and strains of Lyme borreliae (LB) are specialists, infecting only mammalian or only avian hosts (ex. Borrelia afzelii and B. garinii, respectively), while others are generalists and infect both hosts (ex. B. burgdorferi). Such host tropisms are hypothesized to be partially shaped by the ability of these pathogens evade host immune defenses, such as complement. Complement is a first line host defense against invading pathogens that kills LB in vitro and inhibits spirochete …

Development Of Small Molecule Antibiotics Against A Conserved Rna Gene Regulatory Element In Gram-Positive Bacteria, Ville Yrjö Petteri Väre

Legacy Theses & Dissertations (2009 - 2024)

Bacterial infections and the rise of antibiotic resistance, especially multidrug resistant strains, have generated a clear need for discovery of novel therapeutics. Most antibiotics in use today are derivatives of previous antibiotics to which resistance mechanisms already exist, and traditionally they have a single target: either a protein or rRNA. Gram-positive bacteria regulate the expression of several essential genes or operons using a mechanism called the T-box. The T-box is a structurally conserved riboswitch-like gene regulator in the 5’-untranslated region (UTR) of numerous essential genes of Gram-positive bacteria. T-boxes are stabilized by cognate, unacylated tRNA ligands, allowing the formation of …

Regulation Of Gene Expression Through Ribosome-Associated Proteins, Clare Margaret Miller

Legacy Theses & Dissertations (2009 - 2024)

Translation is a crucial mechanism for generating proteins to carry out cellular processes and for ensuring proper cell functions. Ribosomes are at the center of translation and are complex pieces of machinery. They consist of at least 80 core eukaryotic ribosomal proteins, which are conserved from prokaryotes, and four ribosomal RNAs (rRNAs): 18S, 28S, 5,8A 5S. In addition, numerous translation factors aid the ribosome in protein production. While ribosomes are typically described by these core features, they are known to exist in a heterogenous pool with variations in protein composition, modifications of rRNA, and an assortment of non-ribosomal proteins that …

Obituary: Thomas Henry Kunz (1938–2020), Allen Kurta, Winifred F. Frick, M. Brock Fenton, Polly Campbell, Gary F. Mccracken, Robert M. Timm, Hugh H. Genoways

University of Nebraska State Museum: Mammalogy Papers

Dr. Thomas Henry Kunz, an internationally recognized expert on the ecology and behavior of bats and Professor at Boston University, passed away on April 13, 2020 in Dedham, Massachusetts, at the age of 81 as the result of complications from COVID-19. “Tom,” to his many friends and colleagues, was born on June 11, 1938 in Independence, Missouri, to William H. and Edna F. (Dornfeld) Kunz. He married Margaret Louise Brown on December 27, 1962 in Faucett, Missouri, Margaret’s hometown. Two children were born to Margaret and Tom—Pamela Kunz (Jeffrey Kwan) and David Kunz (Nicole, née D’Angelo), and five grandchildren.

As …

Host Transcriptional Response To Persistent Infection With A Live-Attenuated Porcine Reproductive And Respiratory Syndrome Virus Strain, Jayeshbhai Chaudhari, Chia-Sin Liew, Aspen M. Workman, Jean-Jack Riethoven, David J. Steffen, Sarah Vitosh-Sillman, Hiep Vu

Nebraska Center for Virology: Faculty Publications

Both virulent and live-attenuated porcine reproductive and respiratory syndrome virus (PRRSV) strains can establish persistent infection in lymphoid tissues of pigs. To investigate the mechanisms of PRRSV persistence, we performed a transcriptional analysis of inguinal lymphoid tissue collected from pigs experimentally infected with an attenuated PRRSV strain at 46 days post infection. A total of 6404 differentially expressed genes (DEGs) were detected of which 3960 DEGs were upregulated and 2444 DEGs were downregulated. Specifically, genes involved in innate immune responses and chemokines and receptors associated with T-cell homing to lymphoid tissues were down regulated. As a result, homing of virus-specific …

Characterization Of Bacterial Endophytes Isolated From Brassica Carinata And Their Potential Use To Decrease Nutrient Requirements In Crops, Alex Soupir

Electronic Theses and Dissertations

Bacterial endophytes have the capability to enhance plant growth by producing plant growth hormones, solubilizing phosphates, suppressing pathogenic fungi, and reducing plant stress hormones. These capabilities make them desirable limiting the amount of nutrients and pesticides that are applied to crops. Through these assays and isolations, it is possible to identify novel bacterial species. In-vitro testing had shown 9 of the 20 isolates possess the ability to produce indole-3-acetic acid (IAA) with Pantoea agglomerans BC09 producing a concentration of 30.2 ng/μl over 4 days. BC09, Bacillus subilis BC10, and Pantoea sp. BC12 were able to solubilize calcium phosphate, 7 endophytes …

Molecular Facet Of Host-Pathogen Interactions In Fusarium Head Blight In Wheat ( Triticum Aestivum L.), Bimal Paudel

Electronic Theses and Dissertations

Fusarium head blight (FHB) is a severe disease of wheat (Triticum aestivum L.). It not only reduces the quantity of the harvested grains but also decreases the grain quality due to mycotoxins contamination, especially Deoxynivalenol (DON). Qfhb1 (or simply called Fhb1) is the most important quantitative trait locus (QTL) for FHB resistance. Our lab has previously identified wheat gene WFhb1-1 (aka. Wfhb1_c1) as a candidate for FHB resistance gene. Here we report that WFhb1-1 has been cloned. The gene (GenBank # KU304333.1) consists of a single exon, encoding a putative membrane protein of 127 amino acids. WFhb1-1 protein produced in …

Microcystins And Liver Disease Mortality, Insights From An Ecological Study, Rajesh Tirpaul Melaram

Walden Dissertations and Doctoral Studies

Microcystins (MCs) are toxic secondary metabolites produced by freshwater cyanobacteria. Algal bloom subsidence can stimulate MC release, which can impair liver function if orally exposed to in large doses. The purpose of this retrospective, U.S. ecological study was to determine if MC exposure represented an environmental risk factor for liver disease mortality using a socioecological approach. A longitudinal ecological substudy investigated the association between average total MCs in Lake Washington and Lake Manatee and age-adjusted chronic liver disease (CLD)/cirrhosis death rates in Brevard County and Manatee County, Florida (FL). A prediction model of total MCs was deduced by quantifying levels …